With the growth in popularity of recreational camping in recent years, the utilization of recreational vehicles of the types known as "motor homes" and "camper trailers" by the public has correspondingly increased. Such recreational vehicles ("RVs") are often utilized for short stays at campgrounds and the like, and must be parked on ground surfaces which are not uniformly flat and level. As a result, it is desirable, and commonly necessary, for such Rvs to be leveled about an axis parallel to the axle(s) of the RV and about the longitudinal axis of the RV. Leveling about the "axle axis" usually presents a less difficult problem relative to the leveling about the longitudinal axis which has presented more of a problem for the RV users.
Various approaches to vehicle leveling have been attempted and are known in the prior art, but none of the approaches have successfully provided a simple, inexpensive, lightweight, and low maintenance device and method of use to efficiently accomplish the task of leveling both single and multi-axle RVs. Leveling devices are known in the prior art and several approaches disclose the use of automatic leveling systems, typically hydraulically or pneumatically actuated. These approaches are highly effective but suffer the disadvantages of initial high cost, mechanical complexity, heavy weight, and constant maintenance. Accordingly, such systems are typically available only on high cost RVs, making them effectively unavailable to the majority of RV users.
Another approach utilizes manually operated jacks to raise the RV, but that approach has its own disadvantages. Those disadvantages include difficulty of operation, reduction of vehicle stability, unnecessary weight, and maintenance requirements. In another approach, rigid wedges or blocks are placed in front of or behind the wheel(s) on the side of the RV to be raised and the Rv is driven onto the wedges or blocks. Some designs provide depressions in the upper surface of the wedges to receive a portion of a tire to help stabilize the RV without the need for wheel chocks. The use of such rigid blocks presents its own further set of disadvantages, including difficulty of storage and, especially with tandem or multi-axle RVs, the inability to place a wedge of sufficient length between the tires to be elevated and the inability to evenly distribute the load between or among the axles.
U.S. Pat. No. 2,532,149 to Cone discloses a tire chain installer and car mover device which provides a flexible base made of a resilient material such as rubber or the like with a ramp section and a platform section rigidly secured thereto. Cone teaches that the ramp and platform sections are essentially flat except for a short inclined forward portion of the ramp section to facilitate driving the vehicle thereon. Furthermore, the ramp and platform sections are separated, leaving a space therebetween to restrain a vehicle tire from rolling once properly positioned upon the device. This approach does not contemplate use of the disclosed device for vehicle leveling, and even if used as such the device would necessarily allow only a single specific amount of height adjustment to be gained rather than allowing progressive leveling. Devices of this approach also appear to lack the flexibility required to fit such a device between the tires of a tandem or multi-axle vehicle.
U.S. Pat. No. 576,825 to Roemheld discloses a means for raising swing-bridges which provides a plurality of interlocking elongated wedges of increasing height designed to enable the replacement of worn swing-bridge wheels. This approach principally addresses the raising of the entire structure uniformly rather than the leveling of the structure. Furthermore, this approach does not address or provide for flexibility of the interconnected wedges.
U.S. Pat. No. 3,752,441 to Rogers discloses a vehicle wheel elevating and leveling device which provides a plurality of individual step-like sections arranged in end-to-end alignment to form an extendable and retractable telescoping unit. This approach principally contemplates use of the device to only approximately elevate the vehicle to a near level position so as to avoid stabilizing jacks used in conjunction with the device from being overloaded by lifting a wheel of the vehicle off the ground. Consequently, this approach provides a limited leveling capability as dictated by the incremental height of each step-like section.
All known prior art devices which elevate the wheels and tires on one side of a multi-axle vehicle fail to elevate those wheels and tires to the same height. As a result, weight distribution and spring compression among the axles is uneven, reducing stability and increasing the probability of spring overload.
There remains an unfilled need for a simple, inexpensive, and low maintenance flexible leveling device capable of providing an effective means of readily leveling an RV with single or multiple axles, while addressing and overcoming the disadvantages associated with devices known in the prior art.